Woundary ballistics of biological tissue’s plastic deformation on the model of ballistic plastiline using hollow point and shape-stable bullets

Introduction. Modern military conflicts make many challenges for military surgeons associated with the use of new types of weapons – hollow point bullets. The solution to this problem, firstly, depends on studying the characteristics of the terminal ballistics of such ammunition and comparing the data obtained with the characteristics of traditional weapon. The aim of the work is to conduct experimental modeling of the wound canal and residual wound cavity, which is formed due to plastic deformation from hollow point and non-hollow point bullets. Materials and methods. The studies were carried out on 40 blocks of ballistic plasticine, in each of which one shot was fired from an AKS-74 assault rifle and a ZBROYAR Z-10 carbine. Depending on the type of ammunition, the blocks of ballistic plasticine were divided into 4 groups: Group 1 – 10 blocks into which shots were made with 5.45 mm non-hollow point military cartridges with "PS" bullets with a steel core "7N6"; Group 2 (10 blocks) – 5.45x39 mm cartridges with "V-Max" hollow point bullets; Group 3 (10 blocks) – with cartridges 7.62x39 mm; Group 4 (10 blocks) – cartridges 7.62x39 mm with hollow point bullets of the "SP" type. Results and discussion. Only for a 5.45 mm military cartridge with "PS" bullets, both inlet and outlet bullet holes were detected in all 10 observations. When using non-hollow point bullets, the outer area of ​​the bullet inlet correlates with the caliber of the projectile (1.6 times larger when using 7.62 mm bullets). For hollow point bullets, the caliber of the projectile does not significantly affect the area of ​​the inlet (P < 0.05). The expansive properties of the bullet significantly increase the area of ​​the bullet hole by 14.87-31.2 times compared to non-hollow point ammunition. Increasing the caliber of the non-hollow point bullet leads to a significant increase in the area of ​​the sagittal section of the residual wound cavity in 1.59-2.03 times; whereas the expansive properties of the bullet do not significantly affect either the perimeter or the area of ​​the sagittal section of the residual wound cavity. For non-hollow point bullets, the volume of the residual wound cavity is more correlated with the caliber of the bullet (increases by 3.36 times); whereas for an hollow point bullet, its caliber has a smaller effect on the volume of the residual cavity (increases by 1.37 times). The expansive properties of the bullet affect the volume of the residual wound cavity in two ways: for 5.45 mm bullets the residual wound cavity increases 1.49 times, for 7.62 mm bullets it decreases 1.65 times. The use of hollow point bullets of 7.62 mm leads to greater collateral damage (zone of secondary necrosis, molecular shock) due to the scattering of the kinetic energy of the bullet to the elastic deformation of near-woundary tissues compared to non-hollow point analogues. The use of 5.45 mm expansive bullets leads to the formation of a larger volume of irreversible damage due to plastic deformation compared to non-hollow point analogues. Conclusions. The resulting model of plastic deformation of soft tissues, depending on the type of modern small arms, showed the dependence of the spatial configuration of the inlet bullet hole, residual wound cavity and deformation and fragmentation of the bullet on the caliber of the cartridge and its expansive properties.

Forensic Investigation of Bullet Holes for Determining Distance from Glass Fracture Analysis

The study of glass fracture patterns has been of long interest to the forensic community. Fragments of glass can be significant evidence found in the investigation of various types of offenses especially where armed violence is involved on automobiles. Figuring out, whether glass fragments present on crime scene share the same origin as per glass that has been hit by a projectile or any substrate, is quite a success to an examiner because that further leads to the investigation of how and by which means it has done. Holes occurred in the glass at the crime scenes have much importance and many attempts are taken to investigate the properties of these glass holes to find the type, speed, and angle of the projectile which probably produce the hole. For highvelocity projectiles including bullets, these bullet holes in glass can exhibit certain features and fractures. The objective of this research was to determine the distance of shooter from the bullet hole on glass used in automobiles. Bullet holes were prepared and different parameters of glass fractures like bullet hole diameter, cone fractures radius, cone fractures diameter, radial, and concentric fracture count were considered from both front and the backside of the glass. These parameters were observed and analyzed to determine the dependency of these parameters on the variable “distance”. The consistency found in the measurements to conclude our results were checked by goodness of fit test. The study bears great significance as it could lay down a foundation to set a standard parameter to estimate distance of bullet hole from shooter in firing incidents involving glass fracture. This will provide a blueprint to crime scene investigators in order to reconstruct the crime scene for understanding and to take investigation to logical conclusion.

Analysis Gunshot Residue (GSR) – Reconstruction of Crime Scenes

GSR particles from the surroundings of bullet hole have been characterized as a function of primer type and particle distribution. SEM images were used to verify size and shape of the GSR particles and EDS to verify the elemental composition in a single particle. The same specimens are further subjected toTime of Flight Secondary Ion Mass Spectrometry (ToF SIMS) with a view to identify the respective surface chemistry, molecular nature and molecular mass of the GSR particles. Both inorganic and organic components of GSR in the elemental and combined form can be identified using SIMS.Secondary ion mass spectrum and the image analysis are carried out for selected particles. The mass peaks of oxides of lead, barium and antimony apart from the elemental masses are found. The combination of Pb/Ba/Sb and their oxides in a particular particle specifically establish the characteristics of a typical GSR particle. Molecular imaging and the distribution of the components in the GSR particle before and after sputtering are studied. Lead and its oxide are more concentrated in the surface of the particle compared to Ba and Sb. It is evident that SIMS can detect whether the components are either in the elemental or a compound form or a combination of both. The results of ToF SIMS clearly establish the feasibility of utilizing ToF SIMS as a tool for direct characterization of GSR from environmental polluted particles of the same nature for forensic applications.

Linguistic and object-based stance-taking in Appalachian interviews

This article uses data from interviews conducted in western North Carolina in order to examine the ways in which speakers enact authoritative, evaluative, and interactional stances to construct individual identity. In this data, we find a subtle interplay between the content of explicit statements, narrative content, and the use of grammatical features associated with Appalachian English (e.g.a-prefixing, nonstandard past tense), and the use of physical artifacts as sources of stance-taking. This article focuses on two speakers' use of (present and not-present) physical artifacts (a placemat, a Civil War era sword, a lock of hair, and a piece of wood with a bullet hole in it) to enact stances that construct individual versions of an Appalachian identity. What this analysis suggests is that it is not just linguistic choices that contribute to stance enactment, but physical objects as well. (Sociolinguistics, stance-taking, Appalachian English, material culture, language and idenity)*